The present invention relates to chest compression devices and in particular to a high frequency chest wall oscillator device.
Manual percussion techniques of chest physiotherapy have been used for a variety of diseases such as cystic fibrosis, emphysema, asthma, and chronic bronchitis, to remove the excess mucus that collects in the lungs. To bypass dependency on a caregiver to provide this therapy, chest compression devices have been developed to produce high frequency chest wall oscillation (HFCWO), the most successful method of airway clearance. In addition, these devices can be utilized for diagnosis and treatment of pulmonary disorders such as lung cancer, asthma, chronic obstructive pulmonary disease (COPD), tuberculosis, Pneumocystis carinii pneumonia (PCP), inflammation, and infection.
The device most widely used to produce HFCWO is The Vest™ airway clearance by the assignee of the present application. A description of the pneumatically driven system can be found in the Van Brunt et al. patent, U.S. Pat. No. 5,769,797, which is assigned to the same assignee as the present application. Another pneumatic chest compression device has been described by Warwick et al., U.S. Pat. No. 4,838,263.
Pneumatically driven HFCWO produces substantial transient increases in the airflow velocity with a small displacement of the chest cavity volume. This action produces a cough-like shear force and reduction in mucus viscosity that results in an upward motion of the mucus.